PH electrode



FIG. 1 is a perspective view of the top, front and left end of a PH electrode showing our new design;

FIG. 2 is a left end elevational view thereof;

FIG. 3 is a right end elevational view thereof

FIG. 4 is a front elevational view thereof, the rear view being a mirror image thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof. 

The ornamental design for a PH electrode, as shown. 